Tricky one, my sight glass is all over the place.
I added exactly 3.5 liters using measuring cup.
The sightglass was full when the bike was cold with (New Filter)< important fact as the filter is not yet filled with oil.
So I ran the bike to temp-220 and then shut off and recheck
while the bike was level on the ground and dead straight,
I noticed little oil near the oil filter and drain plug so it was confirmed to be
pressure due to too much oil > but when I checked the sightglass
this time the marker was at full as it should?!?!
Anyways I decided to play it safe, I drained about 1.5 to 2.0 liters out
and rechecked it was low after running the bike and shutting it off (At low marker or just below it).
I added 1 Liter exactly checked and added 1oz of oil each time and after running the bike the sightglass
filled up to just below full.
The trickiest oil change I have done to date and this is coming from a Ducati guy.
So as the OP suggest with the addition of fill it up to 3.0 Liters ONLY (if using a new filter or without new filter)
and check the sightglass after getting the bike to temperature where the
(Fan kicks in) shut off and check and add as needed.
It is an advice take it or leave it